1. Field of the Invention
This invention relates to a vehicle audio interface adapter suitable for use in a super live sound system as a vehicle audio system in order that a genuine head unit of the system may be replaced by a commercially available non-genuine head unit.
2. Description of the Related Art
A super live sound system generally comprises a head unit 1, a power amplifier 2, seven to ten loud speakers 3-1 to 3-n, one or a plurality of dedicated connectors 4 and 5 connecting the head unit 1 to the power amplifier 2 and the like, and one or a plurality of dedicated connectors 6 connecting output of the power amplifier 2 to the loud speakers 3-1 to 3-n, as shown in FIG. 1.
A digital control type power amplifier 2 is employed in some setting so that a digital sound processor (DSP) function, balance, fader, sound volume, equalizer, etc. are controlled on the basis of setting information transmitted from the head unit 1 serving as an operating section, in a digital communication manner.
In the foregoing digital control type power amplifier 2, on-off control of a power supply is also carried out in the digital communication manner. Accordingly, when the head unit 1 is replaced by a commercially available non-genuine deck having no communicating function, the power amplifier 2 fails such that no sound is produced. Thus, an adapter used for replacing the genuine head unit with a commercially available non-genuine deck needs to have a function replacing the communication of the foregoing head unit 1.
Therefore, an object of the present invention is to provide a vehicle audio interface adapter which can be used when the genuine head unit is replaced with a commercially available non-genuine head unit, and which can provide presence or realism in the super live sound system with the use of a genuine power amplifier.
The present invention provides an audio interface adapter used with a vehicle audio system including a power amplifier, a genuine head unit serving as a tuner and including an operation panel, the power amplifier and the operation panel of the head unit being provided with respective microcomputers and connected with each other by a LAN cable, and a plurality of loud speakers provided in a vehicle interior, the audio interface adapter being interposed between a non-genuine head unit and the power amplifier when the genuine head unit is replaced with the non-genuine head unit, the audio interface adapter generating a LAN signal so that the power amplifier is controlled.
In a preferred form, the audio interface adapter further comprises a transformer incorporated therein for matching an input level of the power amplifier with an output level of the non-genuine head unit.